Sleep is one good blessing that God has given to all human beings on Earth. Sleep is in one way the opposite of awakening. What are the factors available during awakening should not be present during sleep as far as possible. To begin with, we are awake in day time and sleep during night. Day time we have sunlight and in night the little light of moon or no light. We normally have noise of all kinds in day. In the night we hear only specific sounds like sound of insects. So far we dealt with only external factors. What happens inside a man? A man becomes tired by the end of the day and his body is ready to sleep. Deep sleep is equivalent to half death. Before going further let us know about the components of a human body.
A human body consists of three major parts namely body soul and spirit. During sleep, the body part will remain and the spirit will go out of the body. While dealing with spirits one should remember that normally, day is for human beings and night is for spirits of all kinds. The word spirit implies that it will roam. It cannot remain inside a body always. Soul is a component in a body that it will control all organs in the body. The value of soul is beyond the imagination. The soul is a most secret thing inside a man. If a soul leaves the body what will happen is that all organs will function but cannot be operated. If a soul leaves the body permanently it will lead to death. Soul is one of the fastest moving components than others.
Even when a soul is away from a body say to moon, it is considered near to the body because of the speed in which it travels. Spirit and soul leaving the body together, with the body ready to go into sleep, is one of the major factor for deep sleep. Spirit after leaving the body goes to spirit world, from where it came. Both spirit and soul come under God, but soul can be controlled by Holy Spirit. A large number of human beings have seen the spirit but not the soul. There is a possibility that when spirit leave the body, another spirit may come near the body. In such case sleep will be induced by the spirit of unknown spirit. Sleep is more a spirit than body activity. That is why any dose of tranquilizers will not workout sometimes.